The present invention generally relates to a device that may be used to permanently or removably connect a duct (such as a length of pipe or tubing or a container spout) to an object (such as a pipe fitting, a piece of equipment, a tank or other container, or another duct), as well as methods of using the device. More specifically, the device may be used to connect ducts having different sizes and characteristics to the object. In a preferred embodiment, the device acts as a coupling apparatus to connect pipes or tubing having a range of diameters and thread styles to a given object. For example, a single device may be used to join an object to a standard garden hose, a ¾″ nominal diameter steel pipe having NPT threads, or a 1″ Type L copper pipe.
It is to be noted that the device of the present invention is not limited to use with lengths of pipe and tubing alone. It may also be used with other types of ducts, such as conduit, tubing (including medical or food grade tubing), pipeline, hose, channel, vent, a container spout, or other similar ducts or combinations of such ducts, including those having different cross-sectional shapes (such as square or hexagonal). It is also to be noted that the device of the present invention may be used for ducts transporting gases or liquids or both, so that references to a “fluid” herein are intended to refer to both gases and liquids. In various embodiments, the device may also be used to connect one or more ducts to one or more objects.
Apparatus currently exist in the relevant art that are used to connect lengths of pipe and tubing together. For example, copper pipelines often utilize copper fittings, such as standard couplings, tees and elbows, to connect lengths of copper pipe together. Typically, neither the lengths of pipe nor the fittings have threads. Instead, the fittings have openings therein that are designed so that the entire circumference around the end portion of the pipe is held snuggly against the interior surfaces of the opening in the fitting. The end of the pipe is inserted into the opening in the fitting, and a flux/solder (such as lead-based solder) combination or solder (such as silver solder) is used to create a fluid-tight seal between the fitting and the length of pipe. Plastic pipelines, such as those constructed of polyvinyl chloride (PVC), often utilize plastic fittings that are not threaded and function in a manner similar to the copper fittings. In these cases, the end of the length of plastic pipe is inserted into the opening in the fitting, and the pipe is held snuggly against the interior surfaces of the opening in the fitting. A fluid-tight seal is created by using a primer/PVC glue combination on the interfacing surfaces of the pipe and fitting. Some pipelines, such as those constructed of steel, brass, and sometimes plastic, typically utilize fittings, such as couplings, tees and elbows, in which the lengths of pipe have a threaded end and the fittings have a corresponding threaded opening. In these cases, the threaded ends of the pipes are screwed into the threaded openings in the fittings. The fluid-tight seal between the end of the length of pipe and the fitting may be created by the fit of the threads themselves, or by use of a sealing compound in conjunction with the threads.
As yet another example, some coupling devices utilize a compression-type means. In these devices, a gasket or ring (typically of rubber, plastic or metal) may be positioned on a portion of the length of pipe at or near the end thereof, the end of the pipe is inserted into the coupling, and the coupling has a means to compress the gasket or ring against the end or outside surface of the pipe to form a fluid-tight seal and to hold the pipe in position relative to the coupling device. Still other devices may utilize grooves that are cut into the outside surface of the length of pipe and corresponding fittings that fit into the grooves to form a fluid-tight seal and hold the pipe in position relative to the coupling device.
In each of the coupling devices described above, however, the fittings are generally designed to be used with ducts having limited characteristics. For example, a ¾″ black steel tee having NPT threaded openings can only be used with ¾″ nominal diameter pipe having NPT threads on the end of the pipe to be connected to the tee. This tee cannot be directly used with 1″ Type L copper pipe. Nor can the ¾″ nominal diameter pipe be used with a standard garden hose because the NPT threads on the end of the pipe do not match the threads in the end opening of the garden hose. As another example, a ½″ copper coupling can only be used with ½″ nominal diameter copper pipe. The coupling cannot be directly used with ½″ PVC pipe.
There are, however, instances where it may be desirable to connect ducts (such as lengths of pipe or tubing) to objects (such as equipment or containers or other ducts), but a single conventional coupling device is not available to make the desired connection. For example, a person may desire to connect a standard garden hose to a ¾″ PVC pipe, but a conventional adapting connector is not available. In such cases, the means to make the connection may be inconvenient, difficult, or sometimes even impossible to obtain under the circumstances. Thus, there is a need for a single device that may be used to connect ducts having a variety of different sizes and characteristics (such as thread type and style) to a given object, such as an item of equipment, a tank or container, or a length of pipe or tubing. A device of this type may be used as a variable joint to make a fluid-tight connection as part of a variety of different types of conventional connecting devices (such as those described above) and a variety of different types and sizes of ducts. In addition, a device of this type may reduce the expense required to make such connections because only one device, as opposed to a combination of conventional coupling devices, is necessary to make the connection. Further, because of the flexibility in use of the device, it may be possible to reduce the number of fittings that need to be maintained in inventory because one device may be used for a number of different connection types that would otherwise require multiple conventional coupling devices. For example, a plumber may need to carry only a few of the devices of the present invention on his or her service vehicle, as opposed to a multitude of different types of conventional coupling devices. Further still, when incorporated as part of an item of equipment, the device may enable a multitude of different sizes and types of ducts to be connected to the item of equipment, as opposed to a conventional coupling device that requires use of a specific type and size of duct. Thus, only a single variable joining device, as opposed to multiple conventional coupling devices, would be required for an item of equipment intended for distribution to countries using metric sizes of ducts, as well as countries using ducts having English units of measurement.